Abstract

For many years now, end-pumped (often diode-pumped) mode-locked lasers have exhibited pulsewidths significantly shorter than predicted by homogeneous mode-locking theory.¹ We show that the effects of spatial hole burning (SHB) significantly reduce the pulsewidth in end-pumped lasers when the gain region is at one end of the laser cavity and when its length is on the order of the pulsewidth. This occurs because the frequency separation between modes that fill the available spatial holes increases as the gain region is moved from the middle of the cavity to the end of the cavity. This results in an effective inhomogeneously-broadened linewidth which allows for shorter pulse generation and shorter modelocking build-up time.

© 1994 Optical Society of America